Tuesday, March 13, 2012


There's a fascinating piece in Biology News Net about the amazing variety of tools ants use to navigate their way home from a foraging trip:
Desert ants have adapted to a life in a barren environment which only provides very few landmarks for orientation. Apart from visual cues and odors the ants use the polarized sunlight as a compass and count their steps in order to return safely to their home after searching for food.

In experiments with ants of the genus Cataglyphis in their natural habitats in Tunisia and Turkey, behavioral scientists of the Max Planck Institute for Chemical Ecology in Jena, Germany, have now discovered that ants can also use magnetic and vibrational landmarks in order to find their way back to their nest − a small hole in the desert ground. In addition, carbon dioxide produced by their nestmates' breathing also helps homing ants to pinpoint their nest entrance. Hence, the ants' navigational skills prove enormously adaptable to their inhospitable environment.
Visual cues, chemical odors, polarized light, counting into the hundreds if not thousands, magnetic fields, vibrations, and CO2 density gradients - all this processed in a brain scarcely larger than the period at the end of this sentence.

I never cease to be awed by the power of dumb luck and natural selection to produce the most astonishing prodigies in nature. If I hadn't read my Dawkins and my Dennett, and been reassured by these worthies that this sort of thing is child's play for unguided natural processes, I'd be sure there must be some kind of intelligent guidance behind the appearance of such marvels in so tiny an organism.

This video gives an inkling of Cataglyphis' many talents: